The TARDIS arrives on the planet Frontios in the far future, where the
last vestiges of humanity crashlanded years earlier. The struggling
colony is beset by disasters, including deadly meteorite showers and the
disappearance of several prominent colonists who have been sucked down
beneath the ground. The Doctor, Tegan and Turlough discover that the
culprits are the Gravis and his Tractators, giant insects with
incredible powers over gravity. The Gravis intends to transform Frontios
into an enormous spaceship, and spread the terror of the Tractators
across the galaxy.

Production

In the summer of 1982, former Doctor Who script editor
Christopher H Bidmead was contacted by Eric Saward, his old job's
current incumbent. Bidmead had written the two Doctor Who serials
which had bridged the transition from Tom Baker to Peter Davison -- Logopolis and Castrovalva -- and Saward invited him to
contribute new story ideas for the programme's twenty-first season.
Bidmead was happy to return to Doctor Who, but was less than keen
on producer John Nathan-Turner's desire that he develop a
monster-centric adventure, which would represent a significant departure
from his earlier scripts.

Despite his reservations, Bidmead developed a storyline called
“The Wanderers”, commissioned on August 24th. In compliance
with Nathan-Turner's request, “The Wanderers” incorporated
the gravity-controlling Tractators, which were inspired by the wood lice
which had infested a former residence of Bidmead's. The desolate,
Blitz-like setting was influenced by contemporary reports of fighting in
Beirut during the 1982 Lebanon War. Bidmead also wanted to put the
Doctor in a situation where he was very vulnerable, and so he devised
both the far-far-future timeframe and the apparent destruction of the
TARDIS.

The excavation machine was envisioned as being made from
the remains of the colonists kidnapped by the Tractators

On November 26th, Bidmead was contracted to provide the scripts for
“Frotious”: this was one of several misspellings of the
actual new story title, Frontios. (Others which would plague the
production process included “Frontious” and “The
Frontios”.) The major change that Bidmead's story underwent was
the conception of Tractator technology. Both the excavation machine and
a translating device which was intended to float beside the Gravis were
originally envisioned as being made from the remains of the human
colonists kidnapped by the Tractators. These ideas were deemed too
gruesome, however, and were scaled back as much as possible.

Saward also rewrote the serial's final scene as a cliffhanger
introduction to the next adventure, his own Resurrection Of The Daleks. Under the title
“The Return”, this story had been planned as the finale for
Season Twenty, but had been postponed due to an industrial dispute. The
serial that wound up concluding the twentieth season, The King's Demons, was originally meant to
have a cliffhanger ending to lead into “The Return”, and
Saward largely reused this material for Frontios.

Frontios was designated Serial 6N, and was assigned director Ron
Jones, who had most recently helmed Arc Of
Infinity a year earlier. At Jones' instigation, the Gravis'
translation device was completely removed from the scripts; Jones feared
that it would limit his selection of shots, and could be achieved only
with considerable effort while offering little substantive gain.
Initially, Jones' designer was to be Barrie Dobbins. Sadly, however,
Dobbins committed suicide in early July 1983, after completing much of
the preparatory work for Frontios. Dobbins' assistant, David
Buckingham, was asked to take his place.

Dobbins' death was not the only tragedy to afflict Frontios. As
Mr Range, Jones cast veteran performer Peter Arne, who had appeared in
numerous television programmes (including The Avengers and
Triangle) as well as various feature films such as Chitty
Chitty Bang Bang, Victor/Victoria, and three Pink
Panther movies. On August 1st, Arne was fitted for his Doctor
Who costume. Soon after Arne returned home, neighbours reported a
violent argument in his apartment, and the police arrived to find that
Arne had been beaten to death. Several days later, the body of a local
vagrant, with whom Arne had been associated, was pulled from the Thames.
An inquest determined that the vagrant had murdered Arne and then
drowned himself, although the motive for Arne's death was never
uncovered. Meanwhile, Jones found himself forced to hastily recast the
role of Mr Range under very unpleasant circumstances. William Lucas, who
had starred in The Adventures Of Black Beauty, agreed to replace
Arne.

Christopher Bidmead had conceived the Tractators as being
able to curl up into a ball

Earlier in Season Twenty-One, costume woes had plagued Warriors Of The Deep, and these resurfaced to
plague Frontios as well. Bidmead had conceived the Tractators as
being able to curl up into a ball, killing their victims by encircling
and smothering them. With this in mind, Jones hired dancers and actors
with similar skill sets to play the monsters. Unfortunately, visual
effects designer Dave Havard's realisation of the Tractators was very
constraining and inflexible, forcing Jones to abandon these plans. Jones
was also unhappy with Havard's design for the excavation machine, and
decided to shoot around it as much as possible.

On August 19th, during rehearsals for Frontios, the BBC announced
that Colin Baker had been cast as the Sixth Doctor. In fact, Baker had
agreed to replace Davison two months earlier. Production on
Frontios then began on August 24th. Since the Doctor Who
budget would be sorely taxed during the making of the next two serials
-- the action-packed Resurrection Of The
Daleks and Planet Of Fire, which
would be recorded in the Canary Islands -- it was agreed that money
would be saved by confining Frontios entirely to the studio. This
marked the first time since Kinda two years
earlier that a serial had enjoyed no filming whatsoever, be it on
location or at the Ealing Television Film Studios.

As a result, Frontios was made in two three-day studio sessions,
in BBC Television Centre Studio 6. The first block spanned August 24th
to 26th, and largely concentrated on scenes in the tunnels and caverns.
Other sets used on these days included the excavation area and the
research room hatch on the 24th, the TARDIS console room on the 25th,
and the medical shelter on the 26th.

The second studio block took place from September 7th to 9th, and
focussed on scenes in the human colony; Lucas was now battling the flu.
The first day dealt with material on the high street, at the colony ship
entrance and hull, and outside the medical centre. On the 8th, recording
involved sequences on the hull, in the TARDIS console room, and in the
research room; additional material in the tunnels which had been
postponed from the first studio session was also completed. The TARDIS
console room was again required for the final day of recording, which
also dealt with scenes in the corridors of the colony ship and in the
state room, alongside various effects shots. Unfortunately, the
recording fell badly behind schedule over the course of the six-day
shoot, and although Jones managed to capture all of the required
footage, there was little margin for error. At one point, for instance,
Jeff Rawle (Plantagenet) put his foot through a stair, and was
astonished when no retake was requested.

Christopher Bidmead was asked to write a new story teaming
the Tractators with the Master

Episode one of Frontios badly overran, forcing Jones to make a
number of trims. Much of the excised material involved Cockerill and
explored his deepening sense of rebellion. Also cut was a scene in which
Tegan and Turlough return to the TARDIS and find it surrounded by
curious colonists; this is why Turlough later quips that the time
travellers have lost their “news value”. Cut from part three
was the revelation that the voices of the Doctor and Tegan have echoed
through the Tractators' tunnels, explaining how the Gravis is aware of
the Doctor's intelligence.

Despite the difficulty in realising the Tractators, the monsters were
popular with the Doctor Who production team. On March 5th, 1984,
Saward wrote to Bidmead and asked him if he would be interested in
writing a new story teaming the Tractators with the Master. Nothing came
of this idea, but Bidmead continued to work with Saward, writing two
further Doctor Who scripts -- “In The Hollows Of
Time” and “Pinocotheca” -- over the next two years.
Neither of these would be produced, however, and Frontios became
Bidmead's last televised Doctor Who serial.